Drug-Eluting Stent Thrombosis:

A perspective for our patients and colleagues.

The concern about adverse events with drug eluting stents including stent thrombosis (clotting) and heart attacks or deaths associated with stents has gained widespread media attention in the past several months.  This document is intended to provide a perspective on this issue, as well as recommendations.  It incorporates available information from a recent FDA panel review of this issue. 

Drug eluting stents (DES) were first approved in 2003, representing a milestone in interventional cardiology, dramatically reducing restenosis (reclosure of the artery) from what occurred with bare metal stents or balloon angioplasty.  They were widely and rapidly adopted by the cardiology community, reducing the need for repeat procedures in a large number of patients. 

Stent thrombosis was an event seen with prior bare metal stents.  It was generally an “early” event seen within 6 months of implant.  The concerns raised with drug eluting stents are twofold:  1) that these stents can clot later, and 2) that the rate of thrombosis is higher than with bare metal stents.

What can we conclude at this point in time?

1. First it is important to realize that all medical procedures and therapies require a risk/benefit assessment as they are applied.  This is true of DES as it is true of aspirin or warfarin usage.  Aspirin for example is associated with an increased risk of bleeding and some forms of stroke (hemorrhagic), while it is associated with a reduction of nonhemorrhagic stroke and heart attacks and death.
   
   
2. DES is a safe and effective therapy for appropriately selected patients, but not without risk.  The serious risk of stent thrombosis appears to be small, but real (about 1/200, and possibly higher in “high” risk patients), and must be balanced against the need for therapy, and the risk of alternative therapies (eg coronary artery bypass surgery which has risk as well).  It is an event that can occur long after the stent is implanted, rarely years later.  We must not lose focus on the benefits side of the equation as well, including the many patients who experience no harm and receive the benefits, often avoiding the risk of further and alternative revascularization procedures.
   
   
3. Understand the importance of adherence to your medication regimen before and after DES implantation:
   • Aspirin generally for life and for a minimum of 1 year after stent implantation.
   • Plavix therapy is officially recommended for a minimum of 6 months. 
     Based upon the FDA review, Plavix should now be continued for 1 year and in selected individuals indefinitely.
     • Never stop your Plavix or aspirin without talking with the cardiologist who implanted your stent.    For example, sometimes a dentist, surgeon or other healthcare provider might ask you to stop aspirin or Plavix prior to a procedure; DO NOT stop unless you have first spoken with your cardiologist.
     • If you or your cardiologist believe you will be a poor candidate for prolonged therapy with aspirin and Plavix (e.g. the need for an operation, inability to comply with prolonged therapy due to financial or other constraints, etc, need for warfarin therapy), an alternative revascularization strategy may be appropriate. 
   • If you have stopped your Plavix greater than 2 months ago, aspirin alone is reasonable therapy.  If you have questions about this, contact your cardiologist.